GREAT video... Thank you

Couple of important points that were missing. For in mast furling what about spar weight. A closed tube is much stronger than an open tube so how much heavier does the spar have to be? Also on mainsails with in boom as soon as you roll any sail you no longer have an outhaul so cannot flatten the sail in stronger winds. On headsail furling they did not mention the limits. Never seen a headsail that can be reduced more than 10% without losing all effectiveness. Unless you have a multiple headsail system this leaves you stuck over a major part of the wind range particularly for sailing upwind. These systems may be good for short handed boats, particularly with families, where they need a big boat for accommodation but don't have the crew strength to run it and will only use the boat for short local trips where they can motor back to harbour if conditions deteriorate. For serious cruising particularly for offshore passages these limitations are very significant. I think this video glossed over the limitations far to much and implied that they are not significant, clawing off a lee shoe in a 30kn squall with only a furled 120% genoa you soon find out how significant they really are.

No cost comparisons between types and manufacturers.

Bottom-up furlers won't work well on full bodied headsails (true spinnakers) and the top down models have been a godsend for those sails where you previously had to either sock or snuff a big full bodied spinnaker.

What are the NS lofts that have the infrastructure to manufacture 3Di sails today? Is this technology available in all NS lofts or only in specific countries?

“Gravity” 🤦🏻‍♂️🤣